The present invention applies to the art of stud end welding and, more particularly, to a stud end welding system which includes a stud welding gun which is interactive with the stud welding power supply and control circuitry to provide predetermined lift, hold and plunge of the stud.
A typical stud welding system will include a power supply and associated control circuitry operating in conjunction with a stud welding gun.
A typical stud welding gun is the type which includes a gun body and movable therein a gun shaft which includes a stud chuck at one end thereof. The opposite end of the gun shaft positioned within the stud welding gun body cooperates in conjunction with a clutch mechanism.
The typical stud welding gun will include an electric solenoid which is interconnected to the clutch mechanism. When the gun is positioned in place for welding, the clutch mechanism will permit the gun shaft assembly and the stud within the stud chuck to assume a reference data plane.
The power supply and control circuitry is interconnected to the trigger of the stud welding gun. Upon closure of the gun trigger, the gun solenoid retracts the gun shaft assembly and included gun chuck and stud a predetermined distance The control circuitry within the power supply then releases the gun solenoid which is biased by spring means toward the plunge direction. In some cases, the plunge may be appropriately dampened either pneumatically or hydraulically.
The length of plunge in a typical stud welding gun is controlled by the distance the stud must travel to reach the molten pool of metal at the workpiece. This essentially is the sum of the amount of lift plus the burnoff of the stud. In a like manner, the speed of the plunge is controlled by the spring pressure and the dampening effect of any dampening mechanism all of which can wear or fall out of adjustment and thus become inconsistent. Thus, too slow of a plunge will result in improper fusion bonding of the stud with the workpiece while too fast of a plunge will result in splattering of the molten metal. Lastly, the typical length of plunge in conventional stud welding guns is of approximately 3/4" or less.
In a conventional and typical stud welding gun as different sizes or diameters of studs are welded, the internal mechanism of the stud welding gun must be changed to accommodate the differing length of plunge and speed of plunge required.
A stud welding system is needed in the industry which can independently and automatically vary the extent of lift and speed of lift, retention of the stud in lifted position and the extent and speed of plunge over a wide range. The interactive stud welding gun of the present invention provides that flexibility.